Many known access control systems include an anti-pass back (APB) feature that prevents unauthorized users from tailgating an authorized user to gain access to a secured region. For example, when a user presents a valid access card to a card reader to gain access to a secured region, an APB feature prevents an unauthorized second user from using the same card to gain access to the region. Such an APB feature can include dividing a secured region or facility into AREAs, designating different card readers as an IN reader or an OUT reader, and controlling access to the secured region in accordance with three rules: (1) a user presenting a valid card to an IN reader must present the same card to an OUT reader before again presenting the card to an IN reader, (2) after presenting a valid card to an IN reader, a user presenting the same card to the same or another IN reader without presenting the card to an OUT reader will be disallowed access, and (3) after presenting a valid card to an OUT reader, a user presenting the same card to the same or another OUT reader without presenting the card to an IN reader will be disallowed access.
Known access control systems can include a host processing system, one or more SITEs, and one or more AREAs. For example, a host processing system can include any system that is capable of communicating with an access controller and sending an APB status message to the access controller. A SITE can include a logical group or cluster of access controllers based on proximity, region, or location, and an AREA can include a group of IN readers and OUT readers that are associated with one or more access controllers and that adhere to the above-identified rules. For example, an AREA can include access controllers from a single SITE and typically does not include access controllers from multiple SITEs.
An APB feature can operate in a facility that includes a plurality of card readers communicating with a plurality of different access controllers. However, several different forms of APB features are known. For example, when a GLOBAL APB feature is employed, a card swipe that occurs on one card reader communicating with one access controller can lead to an APB status message being broadcast to all other controllers in the facility that are participating in the APB feature. When a SITE based APB feature is employed, an APB status message is limited to being broadcast to controllers in a particular SITE and to controllers located in referencing AREAs. When an AREA based APB feature is employed, an APB status message is limited to being broadcast to controllers located in referencing AREAs.
When designing and planning an access control system that includes an APB feature, it is both useful and necessary for an integrator, facility manager, security manager, IT department, and the like to plan for the capacity of the APB feature. For example, it is necessary for such stakeholders to determine whether a host system can support APB performance and whether an APB threshold value will be exceeded. Such planning is useful in at least three situations: (1) when an APB feature is enabled for the first time on an access controller in an existing host system, (2) when an existing APB enabled host system is updated, for example, by adding a new set of APB enabled access controllers to the host system or by adding a new set of AREAs to the host system, and (3) prior to deploying a new host system. For example, an estimated number of APB enabled access controllers that can be supported by the new host system should be identified prior to deploying the system.
When capacity planning is lacking, undesirable results can manifest in operational, performance, and return-on-investment (ROI) issues. For example, when an excessive number of APB enabled access controllers are supported by a single host processing system, the host system may generate a large number of APB status messages responsive to signals from the controllers, but the host system may be unable to process and transmit each status message in a timely manner. Accordingly, card holders may not be able to get in and out of a secured region in a timely manner or to an evacuation region in an emergency situation. Furthermore, when the processing power and time of the host system is consumed with a large number of APB status messages, performance issues may arise in other functional areas of the host system, such as processing events from controllers, acknowledging alarms and operator action, and the like. Finally, when a facility includes multiple host systems and the performance of any individual host system is not optimized, such as a host system processing a number of APB status messages that is less than a threshold number, the overall total number of host systems can be reduced by consolidating host systems, thereby improving on a ROI in terms of the hardware, software, monitoring personnel, IT personnel, and the like required for each host system.
However, when capacity planning is performed properly, stakeholders can make appropriate corrective decisions, such as whether to add additional host systems, consolidate access controllers for multiple host systems, or change the configuration for an AREA in the system, such as, for example, an APB type (GLOBAL, SITE based, or AREA based), in order to optimize the operation, performance, and ROI of the system. Accordingly, there is a continuing, ongoing need for systems and methods of predicting APB capacity.